[saba]

why should be the chloride ion removed from precipitate?
Test the filtrate on all samples for the completeness of precipitation by adding a little more
dimethylglyoxime (2 - 3 mL). If any red precipitate forms, reheat the solution on the hot plate
after raising the pH to 7. When you are finished filtering, was the precipitate with cold water
to which a few drops of ammonia have been added (do not used distilled water without this
precautionary measure). Continue washes until the washings are free form chloride ion (use
acidic AgNO3).

[Borek]

What does presence of Cl^- mean? Or what does it suggest? Is it possible than ONLY Cl^- is present in the solution?

[saba]

Hi
this is a standard procedure.
what interfering effect has chloride ion?

http://chemlab.truman.edu/CHEM222manual/pdf/nickelgrav.pdf

[Borek]

Can you try to answer my questions from the previous post?

[saba]

because of using HCl, Cl- exists in solution.

[Borek]

You have raised pH to 7, so no HCl in solution.

Do you know what a "counterion" is?